CPST vs SEPU: Cap, Buffer & Days Left
As of Oct 9, 2026 SEPU can fall 1.9% before its buffer engages and CPST 0.6%. Net assets: $41m on Oct 9, 2026 for Calamos S&P 500 ® Structured Alt Protection ETF - September, and $165m on Oct 8, 2026 for AllianzIM U.S. Equity Buffer15 Uncapped ETF - Sep.
CPST costs 0.05 points a year less; their one-year returns differ by 6.5 points; SEPU is 4.0 times larger.
| CPST | SEPU | |
|---|---|---|
| Expense ratio | 0.69% | 0.74% |
| Net assets, as of Oct 8, 2026 | $41m | $165m |
| Total return, 1 year | +5.4% | +11.9% |
| What it tracks | SPY | SPY |
| Holdings in common | not published | |
| Index fall to the buffer | 2.2% | 1.5% |
CPST: reference +2.2% since period start, fund +0.5%; buffer Floor; cap +8.1%; Full floor. Figures to Oct 9, 2026.
Figures to Oct 9, 2026.
SEPU: reference +1.5% since period start, fund +1.1%; buffer 0 to −15; no cap; No cap. Figures to Oct 9, 2026.
SEPU: reference +1.5% since period start, fund +1.1%; buffer 0 to −15; no cap; No cap. Figures to Oct 9, 2026.
These are two different products. CPST is a floor fund, which caps how far a holder can fall. SEPU is a buffer fund, which absorbs the first part of a fall and leaves everything below it with the holder.
Where each one stands today
CPST resets first, on Aug 31, 2027, 326 days from now; SEPU runs to Aug 31, 2027, 326 days. A fall from here reaches CPST’s buffer after 0.6% and SEPU’s after 1.9%. Both track SPY, so what separates them is where each is in its own period.
Performance, window by window
| Total return | Gap to the reference's price return | |||
|---|---|---|---|---|
| Window | CPST | SEPU | CPST | SEPU |
| 3 months | +1.2% | +2.3% | −1.9 pts | −0.8 pts |
| 6 months | +3.6% | +11.6% | −11.0 pts | −3.0 pts |
| 1 year | +5.4% | +11.9% | −10.6 pts | −4.1 pts |
Each fund's gap is to its reference's price return, dividends left out: the basis the outcome period uses. Source: ETFIQ. Open the live comparison on ETFIQ →
On the same fields
As of Oct 9, 2026. Source: ETFIQ.
CPST in plain words
The fund's price can fall 0.6% from here before the buffer starts absorbing losses, by the issuer's figure. In index terms, SPY can fall 2.2% from today's level to the point where the buffer begins. Protection left, in index points: 100.0% of the 100.0% buffer still sits below today's SPY level. 326 days remained on Oct 9, 2026. On Aug 31, 2027 the period ends and a new cap is set.
SEPU in plain words
This fund has no cap. It takes a share of any further rise in SPY. The fund's price can fall 1.9% from here before the buffer starts absorbing losses, by the issuer's figure. In index terms, SPY can fall 1.5% from today's level to the point where the buffer begins. Protection left, in index points: 15.0% of the 15.0% buffer still sits below today's SPY level. On Aug 31, 2027 the period ends and new terms are set.
Questions people ask
ETFIQ links to the documents behind every figure; a link is not an endorsement. A comparison is not a recommendation.
How this is computed
ETFIQ calculates every figure from each issuer’s published outcome-period terms. Buffer ETFs hold options on an index, not shares, so there is no holdings overlap to report.
Every figure is an ETFIQ calculation with distributions reinvested.
ETFIQ, CPST against SEPU, data as of Oct 9, 2026. https://etfiq.com/compare/buffer/cpst-vs-sepu
ETFIQ. (Oct 9, 2026). CPST against SEPU. Retrieved from https://etfiq.com/compare/buffer/cpst-vs-sepu
[CPST against SEPU (ETFIQ, Oct 9, 2026)](https://etfiq.com/compare/buffer/cpst-vs-sepu)
Free to use with attribution for figures ETFIQ computes; issuer data stays under its owner's terms.